Automatic pressure-control apparatus



' I 1346,84 Oct. 25,1927. ASTROM AUTOMATIC PRESSURE CONTROL APPARATUS Filed Aug. 21. 1926 2 Sheets-Sheet 1 QM a? w s Ck, w

25 192 Oct 7 J. ASTROM AUTOMATIC PRESSURE CONTROL APPARATUS Filed Aug, 21. 1926 2 Sheets-Sheet 2 Patented Oct. 25, 1927.

UNITED STATES 1,646,847 PATENT OFFICE.

JOHN ASTROM, OF FORT WAYNE, INDIANA, ASSIGNOR TO FORT WAYNE ENGINEERING & MFG. 00., OF FORT WAYNE, INDIANA.

AUTOMATIC PRESSURE-CONTROL APPARATUS.

Application filed August 21, 1926. Serial No. 130,736.

This invention relates to automatic pressure control apparatus.

Objects of this invention are to provide a device which is responsive to variations in pressure, and whichwill open and close a control electric switch in a novel manner.

Further objects are to provide a pressure controlled switch, which is wholly automatic in its action, which has a quick make and break, and will thus prevent arcing and which, therefore, will have a long'life.

Further objects are to provide a pressure controlled switch, in which the exact pressure at which the switch will respond ma be most easily regulated by a simple a justment of one of the parts, in which the device is so constructed that irrespective of the speed of travel of the pressure responsive parts, the switch, nevertheless, is positively thrown open or closed and is held in its open or closed position by means of a locking mechanism.

Further objects are to provide a pressure controlled switch which is very compact,

-' which is easily assembled 'and adjusted, and

which is not likely to get out of order.

An embodiment of the invention is shown in the accompanying drawings, in which z Figure 1 is a side elevation of the dev ce with the cover shown in section and with parts broken away.

Figure 2 is a vertical sectronal vlew through the apparatus, such vlew corresponding to a section on line 2-2 of F ig-- ure 3.

Figures 3 and 4 are sectional vlews transversely of the apparatus on the lines 33 and 44 of Figure 1.

Referring to the drawings, it w1ll be seen that the device comprises a vase 1 which is cup-like and which is adapted to be screwed upon and supported by the pipe 2. This base 1 is internally threaded and receives the removable portion 3, such portion being exteriorly threaded and carrying the upright or in 4. Between the portions 1 and 3 a flexible diaphragm 5 is clamped, such diaphragm being formed of rubber, leather, or'

other suitable material, and suitable recesses, such as those indicated at 6 and 7, being provided for accommodating the bowing of the diaphragm. Preferably a pad or packlng ring 8 is provided to prevent cutting of the diaphragm by the turning of the member 3.

ThlS ring may be of metal or of any suitable material. For example, it may also be formed of rubber or leather, if desired. The member 3 is provided with a cylindrical cavity 9 within which a plunger 10 slides. This plunger has an upwardly projecting pin 11 terminating in a conical upper end.

The portion 3 of the base carries a pair of spaced uprights 12 between which a bell crank lever is pivoted upon a. pin 13. This bell crank lever has an approximately vertical arm 14 and an approximately horizontal arm 15. The horizontal arm is recessed, as lndicated at 16, for the reception of the conical end of the' pinll of the plunger so that the plunger loosely sockets within the lever 15. The lever 15 is further provided with spaced arms at its free end between which a bearing block 17 is pivoted. This bearing block is apertured so as to clear the pin 4 and receives the lower end of the compression spring 18. The up r end of the pin 4 is threaded and an ad usting nut 19 is screwed thereon and bears upon the upper end of the spring 18. By rotating this nut the exact pressure at which the device will operate may be regulated.

Between the upper ends of the "uprights 12 a rocking block 20 is pivotally mounted. This rocking block is rigidly secured to the transverse rock shaft 21. A roller 22 is mounted between a pair of links 23 pivotally carried by the upper end of the lever 14. These links are urged downwardly by means of the spring 24., such spring having one end traversing the links- 23 and having its other end fastened behind pins 25 carriedby the lever 14. Thus the links 23 and consequently the roller 22 are yieldingly urged downwardly against the rocking block 20.

The rocking block, as will be noted from Figure 2, is provided with a pair of outwardly projecting arms which alternately latch upon the shoulders 26 of a pair of pivoted latches 27. These latches are urged inwardly by means of "the tension spring 28 so. that one or the other of such latches engages beneath the arm of the rocking block.

The rock shaft 21 projects outwardly beyond the uprights 12, as may be seen from Figure 4, and a pair of blocks 29 are clamped thereto. These blocks rigidly carry a pair of downwardly extending insulating rods 30. The lower ends of the rods 30 are transversely apertured and pins 31 are slidably mounted in such apertures. These pins are urged inwardly b means of the springs 32. The inner ends 0 the pins carry the arched contact brushes, or movable contact members, 33. These members 33 engage the contact strips or stationary contacts 34 carried by the insulating blocks 35 mounted on opposite sides of the uprights 12 and secured thereto by means of the bolts 36, as most clearly shown in Figure 3. The stationary contacts 34 are channel-shape and are bolted about the ends of the blocks 35 so that they maybe retained in place by means of the screws 37, such screws also being adapted to receive the terminals or wires, (not shown).

It is to be noted that the contacts are duplicated on opposite sides of the apparatus so that if one contact becomes fouled or defective, the other contact can still function, and, consequently, the switch has a greater effective life and is more reliable than would otherwise be the case.

The operation of the apparatus is as follows: Assuming the parts are in the position shown in Figures 1 and 2, it will be seen that the switch is held closed by means of one of the latching members 27. However, as the pressure increases the plunger moves upwardly and consequently rocks the lever 14: outwardly. This causes the roller 22 to travel across the upper face of the rocking block 20, the spring 24 applying pressure to the roller. This travel of the roller continues until it contacts with the operative latch and unseats such latch. The rocking block 20 is quickly rocked to the other position from that shown in Figure 2, and consequently snaps the switch members apart.

It is to be noted that after this action has occurred the opposite latch from the previously active one comes into position and locks the switch in open position. The reverse action of the device is obvious from the description thus far given. It is to be noted that the springs 32 allow the brush members certain amount of yield with respect to th rods 30.

It is to be noted, also that the brush members or movable contacts 33, are themselves yielding, and sudden and positive contact is thus assured.

Further, it is to be noted that on the opening movement the rods 30 are snapped outwardly in a very quick and rapid manner when the rocking block 20 is released. lln addition to this the springs 32 maintain the contacts in engagement with each other until a certain amount of movement of the rods 30 has taken place. When the rods 30 contact with the springs 32, the contact members 33 are suddenly jerked clear of the stationary contacts.

Further, it is to be noted that the entire device is housed by means of a cylindrical casing or shell 38 which fits over the base member and is readily removable. Obviously the adjustment of the device is easily effected by means of the nut 19, such nut controlling the pressure of the spring 18. In this manner the exact pressure at which the device will operate may be easily controlled.

If desired, means may be provided for limiting the outward motion of the rods 30. For example, one of the blocks 29, as shown in Figure 1, may be provided with a tongue 39, which contacts with a pin 40 and thus limits the outward motion of the rods.

It is to be noted further that the several parts of the device may be easily adjusted. F or example, the blocks 29 may be adjusted with reference to the rocking shaft 21 by loosening their clamping screws and turning them into the correct position. Thereafter the clamping screws are tightened and the blocks rocked in place.

It is to be noted that the arrangement of the roller and the block upon which it bears, is such that a quick motion is imparted to the switch mechanism by its construction alone. However, the latches emphasize this quick motion by freeing the block at the extreme limit of movement of the roller and allowing it to quickly rock the rocking shaft and consequently quickly operate the switch mecha- IllSIIl.

Further it is to be noted that the parts are extremely simple and are readily produced by ordinary machine shop methods.

It will be seen, therefore, that a very simple and effective type of pressure controlled switch has been provided.

Although the invention has been described in considerable detail, such description is intended as illustrative rather than limiting as the invention may be variously embodied and as the scope of such invention is to be determined as claimed.

I claim 1. In a device of the class described, the combination of a hollow base having a threaded aperture adapted to receive a pipe, a diaphragm carried by said base and forming a chamber with said base, a plunger bearing upon said diaphragm and having a pointed upper end, a bell crank lever havmg one arm socketed for the reception of said plunger and having the other arm extending u wardly from said base, a rock shaft provided with a bearing block rigidly carried by said rock shaft, a link pivoted to the upwardly extending arm of said bell crank lever and having a member spring pressed against said bearing block, a rod carried by said rock shaft, a movable switch contact carried by said rod, and a cooperating stationary contact supported from said base.

2. In a device of the class described, the combination of a hollow base having a threaded aperture adapted to receive a pipe, a diaphragm carried by said base and forming a chamber with said base, a plunger bearing upon said diaphragm and having a pointed upper end, a bell crank lever having one arm socketed for the reception of said plunger and having the other arm extending carried by said rod, and a cooperating stationary contact supported from said base, said movable contact being relatively movable with respect to said rod.

3. In a device of the class described, the combination of a hollow base, a pair of upright/s extending upwardly from said base,

a bell crank lever pivoted between said uprights and having an upwardly extending arm and a horizontal socketed arm, a diaphragm carried by said base, a plunger bearing against said diaphragm and having an outwardly extending portion seated within-the socket of said lever, a spring urging said lever against said plunger, means for adjusting the pressure of said spring, a transverse rock shaft carried by said uprights, a rocking block carried by said shaft, a link pivotally carried by said upwardly extending arm and having a roller at its free end bearing upon said block and adapted to be drawn by said lever from one side of said rock shaft to the other, means urging said roller against said block, whereby said block is rocked in opposite directions by said roller as the pressure of the roller shifts from one side of the block to the other and switch mechanism operated by said rock shaft.

4. In a device of the class described, the combination of a hollow base, a pair of up rights extending upwardly from said base, a

bell crank lever pivoted between said uprights and having an upwardly extending arm and a horizontal socketed arm, a diaphragm carried by said base, a plunger bearing against said diaphragm and havmg an outwardly extending portion seated within the socket of said lever, a spring urging said lever against said plunger, means for adjusting the pressure of said spring, a

transverse rock shaft carried by said u rights, a rocking block carried by said sha t, a link pivotally carried by said upwardly extending arm and having a roller at its free end bearing upon said block and adapted to be drawn by said lever from one side of said rock shaft to the other, a pair'oi latches located on opposite sides of said block and adapted to alternately engage said block, said latches being unseated by said roller at the limit of the stroke of said roller, means urging said roller against said block, and switch mechanism operated by said rock shaft.

In testimony that I claim the foregoing I have hereunto set my hand at Fort Wayne, in the county of Allen and State of Indina.

' JOHN ASTROM. 

